1. Field of the Invention
The present invention relates to a digital-television receiving antenna, and more particularly, to a compact digital-television receiving antenna.
2. Description of the Prior Art
With rapid development of wireless communication technology, wireless communication applications are more and more popular. Performances of the wireless communication applications are highly related to volumes and functions of antennas thereof. Since analog signals transmitted by analog communication systems are easily interfered during wireless transmission, digital communication systems are being substituted for the analog communication systems. For example, a digital television (DTV) system can perform digital signal processing to discard noise generated during broadcasting, so that the DTV system can prevent snowflakes, ghost images, and increase image quality in comparison with an analog TV system, which follows NTSC (National Television Standard Committee) standard. In addition, digital signals can be compressed to increase the efficiency of frequency utilization. Now, the DTV system has been developed in three main standards, DVB (Digital Video Broadcasting) by European Broadcast Union (EBU), ATSC (Advanced Television Systems Committee) by US, and ISDB (Integrated Services Digital Broadcasting) by Japan.
Plug-and-play (P&P) devices, such as USB (universal serial bus) devices, combining DTV tuners are greatly demanded. Using such devices, DTV signals can be received, demodulated, and transmitted to a desktop or notebook through a USB interface, so that a user can enjoy DTV programs through the desktop or notebook anytime and anywhere. In the prior art, most P&P DTV receivers are connected to external receiving antennas through external wires, which is inconvenient for using. TW patent No. M270,510 discloses a DTV receiving antenna, which functions with a large length and is inconvenient for using. TW patent No. M269,583 discloses another DTV receiving antenna, which is formed as a helix structure and requires high production cost.